
The thing is pink hair feels guilty about the kiss scene, he doesn't like the script and got really worried about it, he even asked the chef to not watch the drama, so when the chef said "he doesn't care", it hurts him... Also about your other comment asking if he wants the chef to be jealous, of course he does, but it's not that he's intentionally want him to be jealous, he doesn't want to do the kiss scene after all, so he doesn't want the chef to get mad at him, but hearing he doesn't care also hurts him because he cares a lot about it
I wonder if it's different culture that makes you asked something so obvious? Maybe kissing is not a big deal for people in your country? I mean here in asia it's a common sense that you'll be jealous if someone you love gets intimate with other person, they who have idols/actors as lovers might be used to it and understand that it's just a professional work, obviously they can't forbid their lovers to do their job, but jealousy is normal (especially them who haven't used to it, some people might stop being jealous after their actor lovers do countless kissing scenes, but this kissing scene is the first for pink hair, he took a big deal of it, feels guilty about it, got really worried if the chef will get mad at him, so hearing the chef doesn't care will be interpreted that the chef doesn't have any feelings for pink hair at all)
I don't like being left hanging...and chef mind your words